Institute of Biology, University of Neuchâtel, CH-2000, Neuchâtel, Switzerland.
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
BMC Biol. 2022 Sep 14;20(1):203. doi: 10.1186/s12915-022-01406-z.
To disperse in water-unsaturated environments, such as the soil, bacteria rely on the availability and structure of water films forming on biotic and abiotic surfaces, and, especially, along fungal mycelia. Dispersal along such "fungal highways" may be driven both by mycelial physical properties and by interactions between bacteria and fungi. However, we still do not have a way to disentangle the biotic and abiotic elements.
We designed and 3D printed two devices establishing stable liquid films that support bacteria dispersal in the absence of biotic interactions. The thickness of the liquid film determined the presence of hydraulic flow capable of transporting non-motile cells. In the absence of flow, only motile cells can disperse in the presence of an energy source. Non-motile cells could not disperse autonomously without flow but dispersed as "hitchhikers" when co-inoculated with motile cells.
The 3D printed devices can be used as an abiotic control to study bacterial dispersal on hydrated surfaces, such as plant roots and fungal hyphae networks in the soil. By teasing apart the abiotic and biotic dimensions, these 3D printed devices will stimulate further research on microbial dispersal in soil and other water-unsaturated environments.
为了在非水饱和环境（如土壤）中分散，细菌依赖于在生物和非生物表面形成的水膜的可用性和结构，特别是在真菌菌丝周围。沿着这些“真菌高速公路”的分散可能既受菌丝体物理性质的驱动，也受细菌和真菌之间相互作用的驱动。然而，我们仍然没有办法将生物和非生物因素分开。
我们设计并 3D 打印了两种设备，这些设备可以建立稳定的液膜，在没有生物相互作用的情况下支持细菌的分散。液膜的厚度决定了是否存在能够输送非运动细胞的液压流。在没有流动的情况下，只有运动细胞才能在有能量源的情况下分散。没有流动，非运动细胞就不能自主分散，但当与运动细胞共同接种时，它们可以作为“搭便车者”分散。
3D 打印设备可用作非生物对照，研究细菌在水合表面（如植物根和土壤中真菌菌丝网络）上的分散。通过将非生物和生物因素分开，这些 3D 打印设备将刺激对土壤和其他非水饱和环境中微生物分散的进一步研究。
